1. Field of the Invention
The present invention relates to an imaging system, and more particularly, to an imaging system which includes an optical fiber array probe, in which an optical fiber lens is formed at one end of two strands of an optical fiber array, integrated with an endoscope, thereby achieving a compact imaging system with high ease of use.
2. Discussion of Related Art
An endoscope has been known as an in-vivo imaging system. The endoscope is composed of a long tube suitable for being inserted into a body of a human or animal, and a lens positioned in a distant tip of the endoscope is frequently used for providing images of internal areas of the body, that is, images of internal organs such as the stomach or intestines. Surgeons or other users of the endoscope may transmit the images to the outside of the body using an optical fiber cable connected with the endoscope.
In an imaging system that examines patients using such an endoscope, provided images provide only structural information about surfaces of organs, and therefore it is difficult to provide a large amount of biochemical information used for diagnosing lesions of the patient by a doctor.
Accordingly, there are many cases in which the doctor cuts a part of a tissue for accurate diagnosis, and then performs a complex process using separate measuring equipment to thereby diagnose the lesions. However, in such a biopsy process, there is a time-consuming problem to find the lesions through a complex process using separate equipment in order to extract biochemical information, in addition to inconvenience of having to cut the tissue.
Accordingly, there is a limitation on rapid and accurate diagnosis of lesions using only a simple endoscope system. Thus, there is a demand for a new technology for providing functional information in a variety of ways as well as structural information of the lesions.
Meanwhile, research on an imaging system using an optical fiber, for example, a fluorescence spectroscopy system, a fluorescence imaging system, or a nonlinear imaging system, has been conducted. These systems provide biochemical information of lesions in addition to structural information thereof, and thereby are able to be utilized as a means for early diagnosis of diseases. In order to utilize these systems as medical equipment for in-vivo diagnosis, the manufacture of a sample arm probe is necessary. The simplest method for manufacturing the sample arm probe is to simultaneously transmit an excitation beam and fluorescence signals or nonlinear signals using a single strand of optical fiber.
FIG. 1 is a schematic view showing an imaging system using a single strand of optical fiber. In such a structure, in order to separate excitation light and fluorescence signals or nonlinear signals generated from a sample to be transmitted and received, an optical splitter in a bulk form and lenses are needed, and this may cause difficulty in optical alignment when configuring the imaging system and complexity of the imaging system.
In order to solve these problems, optical fiber probes with a variety of structures have been developed. In the case of the fluorescence spectroscopy system, a method of separately using optical fiber for transmission of an excitation beam and detection of a fluorescence beam has been proposed. In the methods proposed in the related art, ends of two strands of optical fiber attached side-by-side to each other are used which are simply cut or polished at a predetermined angle.
However, in the case of cutting and using the end of the optical fiber, while the manufacture of the optical fiber probe is simple, the optical fiber is available only in a sample having significantly strong fluorescence signals due to significantly low coupling efficiency of fluorescence signals generated in the sample. In addition, in the case of polishing the end of the optical fiber at the predetermined angle, while improvement in the coupling efficiency of approximately 2 times may be achieved compared to the case of cutting and using the end of the optical fiber, two optical fibers have to be cut at an accurate angle, and therefore the manufacturing process becomes complex. Therefore, there is a demand for a new probe manufacturing method.